Set spanner with free return stroke has gap shaped to enable ratchet effect in reverse direction

摘要

The set spanner has its gap shaped to enable the screw heat to slip, as with a ratchet spanner, when the spanner is turned in the reverse direction. A support element may be fitted on either side to provide axial support for the set spanner, without detriment to the function of fitting the spanner to the bolt head from the side.